Bobbin winding system

ABSTRACT

A system for winding a cross-wound bobbin has a rotatably supported tube holder that is intended to receive a tube. The yarn guide element that serves the purpose of shogging the yarn moves in the direction parallel to the axis of rotation of the tube and is made to execute the oscillating reciprocating motion with the aid of a work cylinder. The work cylinder has the advantage that for braking the kinetic energy at the turning point of the yarn guide element, no additional external energy must be applied. It suffices for the applicable cylindrical chamber to be blocked off. Moreover, the gas compressed in the process can be used to accelerate the piston in the opposite direction. The stored braking energy also can be used simultaneously as acceleration energy. Since in the creation of a cross-wound bobbin many thousand such changes of direction occur, the energy savings are substantial.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a divisional of copending U.S. patentapplication Ser. No. 10/496,274, filed Oct. 4, 2004, which claimspriority from International Application No. PCT/EP02/13124, filed Nov.22, 2002, and German Application No. DE10157303.0, filed Nov. 23, 2001.

FIELD OF THE INVENTION

The present invention relates generally to system for winding bobbinswith cross-wound yarn, and more particularly, to a control for morereliably and efficiently controlling movement of the cross-wound bobbin.

BACKGROUND OF THE INVENTION

In the production of yarn, the resultant yarn, in ring spinning, isfirst wound up in the form of cops. These are small bobbins with arelatively small quantity of yarn. The cops are not suitable for payingout the yarn directly to a yarn-using machine, such as a loom. For thatpurpose, the yarn must be rewound into a cross-wound bobbin from whichthe yarn can be drawn off overhead. Drawing the yarn off overhead isnecessary since only that assures a high yarn draw-off speed withstarting and stopping.

German Patent Disclosure DE 121 963 discloses a bobbin winding systemthat is suitable for creating cross-wound bobbins. For that purpose, thesystem has a rotatably supported tube holder onto which the tubes onwhich the cross winding is created are slipped. For driving the tube orthe cross winding formed on it, a roller or cylinder is provided that isoriented axially parallel to the axis of rotation of the tube holder. Itis held in contact by frictional engagement with the outside of theparticular cross winding formed. To make shogging or movement of theincoming yarn possible, a yarn guide element is provided which can bedisplaced parallel to the axis of rotation of the tube. The yarn guideelement is seated on a cable that travels around three rollers. One ofthe rollers is driven, while the yarn guide element is moved back andforth between the other two rollers. By means of a microprocessorcontroller, which with a sensor detects the rpm of the tube holder, thedrive motor is controlled such that the desired cross winding iscreated.

A high edge buildup on the face ends is intended to be avoided bysuitable control of the motor and thus of the shogging stroke. Thearrangement also is intended to prevent ribbon windings. In ribbonwindings, the yarns in the next winding plus one, with the same windingdirection, would rest directly on top of one another.

However, it has been demonstrated that the known arrangement requiresconsiderable energy. At the end of the shogging stroke, the motor mustbe braked, and with the reversed direction of rotation it must beaccelerated, leading to increased current consumption.

OBJECTS AND SUMMARY OF THE INVENTION

It is an object of the present invention to provide a bobbin windingsystem which requires less energy in reversing movement of the bobbinduring a winding operation.

In the bobbin winding system of the invention, a tube holder is providedthat is rotatably supported about an axis of rotation. A yarn guideelement moves parallel to the axis of rotation of the tube holder and isdriven with the aid of a work cylinder. A fluid supply device isassociated with the work cylinder and is controlled via a control unit.With the aid of the fluid supply device, two cylindrical chambers of thework cylinder are selectively supplied with fluid that is under pressurefor moving a piston in an appropriate direction and the yarn guideelement along with it. The speed at which the piston moves dependsessentially on the inflow speed of the fluid. Braking of the piston isaccomplished practically without energy by closure of the ventingopening of whichever cylindrical chamber is decreasing in volume in theongoing shogging stroke.

With the aid of such novel arrangement, high shogging speeds can bechieved. In particular, it is possible to achieve the reversal of motionof the yarn guide element at the face ends of the cross winding veryquickly, or in other words in a very short distance.

The arrangement moreover is quite flexible in operation, in the sensethat different shogging speeds for the outgoing and the return leg ofthe shogging stroke can easily be established. The requisite ribbonbreaking in the cross winding as well as the axial shifting (jitter) ofthe reversal point also can be generated in order to avoid the edgebuildup.

With the aid of at least one sensor, which functions at least as adigital position sensor, the controller learns that the yarn guideelement is located at the position of the sensor. From the successiveposition measurements and from the knowledge, present in the controller,about the intervening shogging stroke portions, the controller iscapable of controlling the supply of fluid to the particular cylindricalchamber in the manner as described above.

By switching the fluid supply to the particular cylindrical chamber onand off accordingly, the current shogging stroke is terminated at thecorrect point, and the next shogging stroke is started in the oppositedirection.

To set the tube, or the particular formed cross winding, into rotation,basically two types of control units can be considered. In one controlunit, a cylindrical drive roller is provided, which by suitable meanscan be maintained in contact by frictional engagement with the outercircumferential surface of the particular cross winding formed. Thisdrive roller is driven by a motor, which can be effectively operated ata constant rpm. However, a variable rpm drive also could be used.

Alternatively, a motor may be coupled directly to the tube holder in amanner fixed against relative rotation. In that case, the motor musthave a variable rpm if a constant circumferential speed, and thus, aconstant winding speed are to be attained.

Preferably, frequency-regulated alternating current motors or steppingmotors can be used in which a desired rpm can be set directly and veryprecisely, without additional closed control loops for stabilizing therpm.

If the tube holder is driven directly, that is, without a drive rollercontacting the winding, it is possible to readily create bothcylindrical and frustoconical cross-wound bobbins. For that purpose, itsuffices to execute a more or less shortened shogging stroke from onelayer to the next.

For the work cylinder, both work cylinders with piston rods and workcylinders without piston rods can be used. The arrangement with pistonrods may be simpler, but may have the disadvantage that depending on thedirection of motion, the piston has different effective surface areas.The effective piston surface area is less on the side with the pistonrod than on the opposite side, so that for the same fluid pressure,different forces are established. Moreover, the mass to be acceleratedand braked is greater, depending on the mass of the piston rod. On theother hand, sealing is relatively simple.

In the work cylinder without a piston rod, conversely, the effectivepiston surface areas are the same on both sides, and thus the brakingand acceleration behavior of the piston is the same, regardless of thedirection of motion, for a given fluid pressure. On the other hand,sealing can be more difficult, particularly if compressed air is used asthe fluid since a certain amount of leakage can occur.

The fluid supply device may include one multiposition valve percylindrical chamber, and this multiposition valve has one connection forcommunication with the particular cylindrical chamber, one connectionserving the purpose of venting, and one connection that can be made tocommunicate with a fluid pressure source. The valve is positioned asclose as possible to the particular cylindrical chamber to avoid idlevolumes. The avoidance of idle volumes leads to better control andregulation of performance, as well as reducing air consumption. Themultiposition valves may be magnetically controlled multiposition valveswhich are acted upon by the control unit directly.

Instead of using a single position sensor, it also is possible to use aspeed sensor that additionally makes it possible to measure the speed.On the basis of its position, the controller thus receives informationboth with respect to the current position of the piston or yarn guideelement and its speed.

It is possible to use two or even more sensors for the position and/orthe speed. It will be understood that the sensors would be disposedwithin the shortest stroke that the yarn guide element executes.

Other objects and advantages of the invention will be come apparent uponreading the following detailed description and upon reference to thedrawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic perspective of an illustrative winding machinehaving a bobbin holder drive in accordance with the invention, in thiscase having a direct drive for the bobbin holder;

FIG. 2 is a perspective of an alternative embodiment of winding machinein accordance with the invention having a friction roller operateddrive;

FIG. 3 is a perspective of still a further alternative embodiment ofwinding system with a work cylinder having a piston rod; and

FIG. 4 is a perspective of still another alternative embodiment ofwinding system in accordance with the invention having a cable operatedwork cylinder.

While the invention is susceptible of various modifications andalternative constructions, a certain illustrative embodiments thereofhas been shown in the drawings and will be described below in detail. Itshould be understood, however, that there is no intention to limit theinvention to the specific forms disclosed, but on the contrary, theintention is to cover all modifications, alternative constructions, andequivalents falling within the spirit and scope of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now more particularly to FIG. 1 of the drawings, there isshown an illustrative system for winding a cross-wound bobbin 1 Thesystem includes a tube holder 2, which is supported rotatably withrespect to an axis of rotation 3; a drive mechanism 4 for the tubeholder 2; a yarn guide element 5; a work cylinder 6 for moving the yarnguide element 5; a fluid supply device 7 for the work cylinder 6; and acontrol unit 8, which cooperates with sensors 9 and 10.

The tube holder 2 essentially comprises a shaft that is rotatablysupported between two bearing flanges 11 and 12. On at least one end,the tube holder 2 is releasable from one of the bearing flanges 11 and12 so that a bobbin tube 13 can be slipped axially onto it. Byappropriate means located on or inside the tube holder 2, the bobbintube 13 can be fixed by frictional engagement on the outercircumferential surface of the tube holder 2. The tube 13 serves as aholder for a cross winding 14 to be built up on it, with the resultingcross-wound bobbin 1 having two face ends 15. While the illustratedbobbin tube 13 is cylindrical, alternatively it could be conicallyshaped.

On the end of the tube holder 2 that is rotatable in the flange 12 butotherwise is rigidly connected, a pulley 16 is seated on the tube holder2 in a manner fixed against relative rotation; an endless belt travelsover this pulley, and by means of the belt the tube holder 2 is coupledto a drive pulley 18, which in turn is fixed to a motor shaft 19 of thedrive motor 4. The drive motor 4 is a motor of controllable rpm, forinstance a stepping motor or a frequency-regulated alternating currentmotor. For extended service life, it preferably is a brushless motor.

The drive motor 4 is regulated such that the tube holder 2 rotates at aspeed that leads to a substantially constant circumferential speed ofthe particular cross winding 14 formed. Accordingly, when the outerdiameter of the cross winding 14 is small, the rotational speed ishigher, and as the diameter of the cross winding 14 increases, therotational speed decreases, down to a minimal value when the crosswinding 14 is full.

The yarn guide element 5, shown in this case as a simple fork, ismovable back and forth essentially parallel to the axis of rotation 3 infront of the cross winding 14 or tube 13. To effect such movement anappropriate work cylinder 6 of a known type, preferably without a pistonrod, may be used. The work cylinder 6 in this case has an elongatedblock-shaped housing 21, which is formed with a cylindrical bore 22.Moving inside the cylindrical bore 22 is a piston 23, which divides thecylindrical bore into two cylindrical chambers 24 and 25. As is usual inwork cylinders 6 without a piston rod, the cylindrical bore 22 opens outtoward one side in the form of a slot 26 leading to the outside, whichis closed off on the inside by a sealing band 27 and on the outside by aguard band 28.

The piston 23 includes a middle piece 29 and two terminal disklike endpieces 31 and 32, which are cylindrical and have a diametercorresponding to the diameter of the cylindrical bore 22. The end pieces31, 32 form a seal against the wall of the cylindrical bore 22 oragainst the sealing band 27 in the region of the slot 26 with onlylittle leakage. A slight leakage is harmless. For the sake of the lowestpossible energy consumption, the piston 23 should be displaceable in thecylindrical bore 22 as smoothly as possible, and seals at the end piecescan therefore be illuminated.

The end pieces 31, 32 are spaced apart from one another such that thesealing band 27 can be pulled off downwardly and removed from the slot26 in the region of the middle piece 29. In this region, it passesthrough a slotlike opening in an extension 33 that protrudes to theoutside through the slot 26.

A slider 34 to which the yarn guide element 5 is secured is seated forsliding guided movement on the extension 33 on the top of the workcylinder 6. A similar groove is located in the slider 34 for lifting theguard band 28 so that the extension 33 can be extended to the outsidethrough the gap between the lifted sealing band 27 and the lifted guardband 28. In this way, the piston 23 and the slider 34 are connectedmechanically to one another.

Instead of the mechanical connection shown between the yarn guideelement 5 and the piston 23 via the extension 33, a magnetic couplingcould also be employed. In that case, the cylinder needs no lateral slot26, or the seals required by such a slot.

A multiposition valve 35, 36, associated with the fluid supply device isflange mounted to each end of the cylindrical housing 21. The twomultiposition valves 35, 36 each are provided with a respectiveelectrical drive mechanism 37, 38 by way of which an associated valvespindle 39 is to be moved in a valve chamber. By means of themultiposition valve 35, the cylindrical chamber 25 can be made tocommunicate selectively with a venting opening 41 or a fluid supplyopening 42. In a middle position of the valve spindle 39, thecylindrical chamber 25 is hermetically sealed so that no fluid canescape from the cylindrical chamber 25. It will be understood that thebasic construction and operation of such multiposition valves is knownand therefore need not be described in further detail.

The multiposition valve 36 has a similar construction. It is providedwith both an outlet opening 43 and an inlet opening 44. The inletopenings 42, 44 communicate via lines 45, 46 with a source 47 for fluidunder pressure, such as compressed air.

In addition, the two sensors 9, 10 are seated in the cylindrical housing21 in corresponding bores 48, 49 leading inward from the underside.These sensors serve to detect the position of the piston 23, or itspassage past the end pieces 31 and/or 32.

The control of the entire system may be by means of the electroniccontrol unit 8, which preferably is microcontroller-based. Itreceives-signals from an input keyboard 51 as well as signals from thesensors 9, 10 connected via lines 52, 53. Via lines 54, 55, the centralcontrol unit 8 communicates with the electric drive mechanisms 37, 38 ofthe multiposition valves 35, 36, and it furthermore communicates via aline 56 with the drive motor 4 for controlling the rpm thereof.

The system described thus far functions as follows:

After the flange 12 has been pivoted out of the way, the previouslywound, full cross-wound bobbin 1 is pulled off the tube holder 2. Next,a new, empty tube 13 is slipped onto the tube holder 2 and secured thereby frictional engagement or other appropriate securing devices. Now ayarn 57, arriving from a yarn supply not otherwise shown, is passedthrough the yarn guide element 5 and secured to the tube 13 in asuitable way. The yarn 57 comes from a spinning station of a known type,or a yarn package.

Once the system has been prepared to this extent, the user may give thecommand to start via the control panel 51, whereupon the centralcontroller 8 causes two things to happen simultaneously: It switches onthe motor 4 at an rpm that generates the requisite circumferential speedfor the smallest winding diameter. Simultaneously, it begins to triggerthe multiposition valves 35, 36 in alternating fashion so that thepiston 23 executes an oscillating motion in front of the side of thetube 14. The control by the control unit 8 is done in such a way thatthe speed of the piston 23 and thus of the yarn guide element 5 betweenthe two face ends 15 of the cross winding 14 is substantially constant.The ratio between the circumferential speed of the cross winding 14 andthe linear speed of the yarn guide element 5 defines the slope anglethat the yarn winding forms on the outer circumferential surface of thecross winding 14.

If it is assumed that the yarn 57 is to be deposited progressively fromthe left face end 15 to the right face end 15, then the controller 8puts the multiposition valve 36 in a position in which the right-handcylindrical chamber 24 communicates fluidically with the venting opening43. Simultaneously, the control unit 8 keeps the multiposition valve 35in a position in which a fluidic communication exists between thecylindrical chamber 25 and the fluid source 47. As a result, the fluidor compressed air can flow under pressure into the cylindrical chamber25 and displace the piston 23 toward the right.

Just before the yarn guide 5 reaches a position in which the yarn 57arrives at the right-hand face end 15, the control unit 8 switches themultiposition valve 35 into a position in which the cylindrical chamber25 communicates fluidically with the venting opening 41. As a result,the driving force for the piston 23 is immediately switched off. Thekinetic energy of motion still existing and the residual pressure in thecylindrical chamber 25 would cause the piston 23 to continue movingonward by a considerable distance, toward the right, as reviewed in FIG.1.

To make the braking distance as short as possible, the control unit 8simultaneously assures that the multiposition valve 36 moves out of theventing position into the blocking position in which the cylindricalchamber 22 communicates fluidically with neither the venting opening 43nor the venting opening 44. Since this situation ensues just before theend piece 32 on the right reaches the right-hand end of the cylindricalchamber 24 and the gas cushion trapped in it is very small. Even a shortmotion of the piston 23 will lead to a considerable increase inpressure, which together with the vented cylindrical chamber 25 brakesthe piston 23 relatively abruptly. The air compressed in the right-handcylindrical chamber 24 will begin, after the piston 23 stops, to put thepiston 23 into motion in the opposite direction. As soon as the pressurein the cylindrical chamber 24 has dropped below the pressure of thefluid source 47, the control unit 8 moves the multiposition valve 36into the air supply position. In this position, the fluid source 47communicates with the cylindrical chamber 24 on the right, via the line45 and the inlet opening 44. The piston 23 will now move from right toleft and accordingly deposit the yarn 57 in a helical line that extendsfrom the right-hand face end 15 to the left-hand face 15.

This valve position is maintained until the piston 25 has moved the yarnguide element 5 into the immediate vicinity of the left-hand face end15. The control unit 8 will shift the multiposition valve 36 from theair supply position into the venting position and simultaneously shiftthe multiposition valve 35 into the blocking position. Thus the sameprocess as described above in conjunction with the cylindrical chamber24 when the piston 23 reaches the right-hand end is repeated on theleft-hand end for the cylindrical chamber 25.

As can be seen from the foregoing, the novel system for braking thekinetic energy of the piston 23, which drives the yarn guide element 5requires no additional energy. The braking is accomplished simply bycompression of the air in the applicable cylindrical chamber. Thecompressed air can simultaneously be used as an energy storing means foraccelerating the piston in the opposite direction. In each case, thebraking energy employed for compressing the gas upon braking can berecovered upon acceleration. Braking the kinetic energy with the leastpossible amount of energy is significant when cross-wound bobbins arebeing formed since one braking event and one acceleration event eachoccur per layer of the cross-wound bobbin, and one cross-wound bobbinhas several tens of thousands of layers.

By regulating the pressure source 47 or the inflow speed of the fluidinto the cylindrical chambers 24, 25, for instance by means ofappropriate additional flow valves, not shown, or by proportionatelyadjusting the multiposition valves on the inlet side, the speed at whichthe piston 23 moves within the constant speed range can be adjusted. Itis possible as a result to determine the angle that the windings form onthe cross winding 15 within wide limits. It is readily possible toproduce various angles, for instance with the angle upon deposition ofthe yarn 57 being less when the yarn is wound on from the left-hand faceend 15 to the right-hand face end 15 than in the opposite windingdirection. Instead of regulation on the inlet side, regulation on theoutlet side by the multiposition valves or additional proportionalvalves also may be employed.

By slight variations in the stroke that the yarn guide element 5executes, so-called ribbon breaking actions and a scattering of thereversal points (edge shifting) on the two face ends 15 can be broughtabout. The ribbon breaking actions prevent the yarn in the respectivenext windings plus one from being deposited exactly congruently with thenext winding plus one located underneath. Such congruent winding wouldreduce the quantity of yarn to be applied for the same winding diameter.The jitter in the region of the face ends of the wound yarn prevents thereversal points from being located congruently one above the other whichwould cause a high edge buildup. By adjusting the rpm of the motor 4,the slope angle can also be varied.

The “approach” of the yarn guide element 5 toward the applicable faceend 15 is detected with the aid of the two sensors 9, 10, which measurethe travel past the adjacent end piece 31 or 32. The spacing between thetwo sensors 9, 10 is selected such to be less than the least distancetravelled in operation by the yarn guide element parallel to the axis ofrotation 3.

Because of the geometric ratios between the sensors 9, 10 and the twoend pieces 31, 32, the control unit 8 can measure the speed at which thepiston 23 moves from left to right since the last passage, for instanceby the end piece 32 at the sensor 9 until the first passage past thesensor 10. From this speed of motion in conjunction with the location ofthe sensor 10, the controller 8 can estimate how long it will take untilthe piston 23 has transported the yarn 57 as far as the right-hand faceend 15 and the above-described reversal of the valves 35, 36 must takeplace. For the opposite direction, the same logically applies.

In addition, from the transit time of the arrangement in conjunctionwith the yarn thickness, which is input for instance via the keyboard51, and the slope angles input via the keyboard, the controller 8 knowsthe diameter of the cross winding 14 that has meanwhile been attainedsince the beginning of winding and can accordingly, without sensors forthe winding diameter, either readjust the drive motor 4 and/or vary thespeed of motion of the piston 23.

FIG. 2 shows an embodiment which differs from the embodiment of FIG. 1in the manner in which the tube 13 is set into rotation. While in theembodiment of FIG. 1 the tube holder 2 is driven directly by the motor4, in the exemplary embodiment of FIG. 2 a friction roller 65 isprovided, supported so as to be rotatable axially parallel to the axisof rotation 3. The elements for supporting the friction roller 65 arenot shown individually and are well known in the art.

The friction roller 65 is driven directly by the motor 4. With the aidof its bearing device, it is assured that the friction roller 65, whoselength is equivalent to the greatest axial length of the cross winding14, is held in contact by frictional engagement with the outercircumferential surface of the cross winding formed at the time. In thisway, a constant circumferential speed is necessarily generated when themotor 4 drives the friction roller 65 at a constant rpm.

FIG. 3 finally shows an embodiment of the invention in which, instead ofthe work cylinder 6 without a piston rod, shown in FIGS. 1 and 2, a workcylinder 6 with a piston rod 66 is used. Otherwise, the mode ofoperation is as explained above in conjunction with FIG. 1, taking onlythe different operative diameters of the piston into account.

In FIG. 4, an exemplary embodiment of the system of the invention isagain shown in which the work cylinder 6 does not have a piston rod. Theconnection between the piston 23 and the slider 34 is made by a veryflexible member in the form of a cable 68. The slider 34 travels freelydisplaceably on the smooth top side of the work cylinder 6.

The cable 68 is secured to the face end of the slider 34 toward theobserver and from there travels in the direction of the left-hand faceend of the work cylinder 6. A deflection roller 71 is rotatablysupported on the outside of the work cylinder 6 on the face end by abearing block 69. The cable 68 travels around this deflection roller 71.Below the deflection roller 71, the cable passes through a bore 72 intothe cylindrical chamber 25, inside in which it is connected to the endpiece 31. Inside the cylindrical chamber 25, the cable 68 extendscoaxially to the chamber and at the top extends parallel to the flat topside of the work cylinder 6.

Another segment of the cable 68 leads from the face end of the slider 34remote from the observer in the direction of the right-hand face end ofthe work cylinder 6. Here, a deflection roller 74 is supported, againloosely rotatably, with the aid of a further bearing block 73. Theapplicable segment of the cable 68 travels around the deflection roller74, and on the underside of the deflection roller 74 it passes through abore, not visible, into the cylindrical chamber 24. Inside thecylindrical chamber 24, the applicable segment of the cable 68 isconnected to the end piece 32 of the piston 28. The cable 68 can be kepttaut by appropriate spring members.

Upon leftward motion of the piston 23, the slider 34 moves with the yarnguide 5 along the top side of the work cylinder 6 into the correctterminal position, and vice versa. The motion of the slider 34 isautomatically coupled with the motion of the piston 23, but in phaseopposition.

The arrangement shown in FIG. 4 functions dynamically, in the sense thatthe piston 23 is intrinsically constantly in motion during the windingoperation. There is accordingly no necessity to seal off the cylindricalchambers 24, 25 hermetically from the ambient atmosphere. It accordinglysuffices if the cable 68, which is for instance a monofilament, passesthrough the bore 72, or the corresponding bore on the other face end ofthe work cylinder 6, without any special sealing. Leak-free sealing isnot required. It suffices for the cable 68, together with the bore, togenerate throttling with an adequate throttling action. For the same ofminimizing energy consumption of the arrangement, conversely, it isimportant to keep the friction of the entire system as low as possible;besides, otherwise there would be the risk that, because of theenormously high number of motions, a seal would be soon damaged by thecable 68 in any event.

The advantage of the arrangement of FIG. 4 is the same as for thearrangement of FIGS. 1 and 2. The mass of the moving parts is kept verylow, thus reducing the expenditure of energy for braking andacceleration. A further advantage of the arrangement of FIG. 4 residesin the avoidance of complicated sealing bands on the work cylinder 6.The structural design is markedly simpler.

Instead of a cable for coupling the slider 34 to the piston 23, a thinband, such as a steel band also could be used, such as shown in dashedlines at 75. The advantage of the band over the cable is the lesserthickness for the same surface area, so that the bending forces upondeflection over the rollers 71, 74 are kept slight. The service life canbe increased markedly under some circumstances.

From the foregoing, it can be seen that a system is provided for windinga cross-wound bobbin onto a rotatable tube supported on a tool holder. Ayarn guide element that serves the purpose of shogging moves in adirection parallel to the axis of rotation of the tube and is made toexecute the oscillating reciprocating motion with the aid of a workcylinder. The work cylinder has the advantage that in braking thekinetic energy at the turning or reversal point of the yarn guideelement, no additional external energy must be used. It suffices for theapplicable cylindrical chamber to be blocked off. Moreover, the gascompressed in the process can be used to accelerate movement of thepiston in the reverse direction. The stored braking energy can also beused simultaneously as acceleration energy. Since in the creation of across-wound bobbin many thousand such changes of direction occur, theenergy savings are substantial.

1. A system for winding cross-wound bobbins (1) with cross windings (14)having two face ends (15) comprising a tube holder (2) rotatablysupported for movement about an axis of rotation (3), a cross-woundbobbin tube (13) adapted for removable positioning onto said tube holder(2) for rotation with the tube holder; a drive mechanism (4) forrotating the tube (13) in order to wind up a yarn (59) onto the tube(13); a yarn guide element (5) mounted for movement back and forth in alongitudinal direction of the cross winding (14) and tube (3) in orderto shog the yarn (59) during the winding process so as to form a crosswinding (14) on the tube (13); a rodless work cylinder (6) having acylindrical space (22) between opposed end faces with a piston (23) thatdivides the cylindrical space into first and second cylindrical chambers(24, 25), one of said cylinder end faces being formed with a bore (72),a cable (68, 75) extending through said cylinder end face bore andcoupled between said piston (23) and said yarn guide element (5); acontrollable fluid supply device (7) which selectively communicates withthe chambers (24, 25) in order to selectively supply fluid underpressure to at least one of the cylindrical chambers (24, 25) or to ventat least one of the cylindrical chambers such that the piston (23) ismoved with the requisite longitudinal motions for causing said cable tomove said guide element (5); and a control unit (8) for controlling thefluid supply device (7) such that the piston (23) is moved with therequisite motion for the rotating tube (13) or cross winding (14) foreffecting the desired movement of the yarn guide element (5) by means ofthe connecting cable (68,75).
 2. The system of claim 1 in which saidtube (13) has a cylinder shape.
 3. The system of claim 1 in which saiddrive mechanism (14) includes a rotatable drive roller (65) held infrictional engagement with an outer circumference of a cross winding(14) formed on the tube (3), and a motor for driving the drive roller.4. The system of claim 3 in which said motor (4) is operable at aconstant rpm.
 5. The system of claim 1 in which said drive mechanism (4)includes an adjustable-speed electric motor (4) coupled for directlydriving the tube holder (13).
 6. The system of claim 1 in which saiddrive motor (4)is a frequency-regulated alternating current motor. 7.The system of claim 6 in the said control unit (8) controls operation ofthe motor (4) such that the circumferential speed of a particular crosswinding (14) formed on the tube (13) is substantially independent of thewinding diameter.
 8. The system of claim 1 in which said drive motor (4)is a stepping motor.
 9. The system of claim 1 in which said fluid supplydevice (7) includes at least one multi-position valve (36, 37)operatively coupled to each cylinder chamber (24, 25), saidmulti-position valves (36, 37) each including one connectioncommunicating with a respective cylindrical chamber (24, 25), oneconnection (43, 44) communicating with a fluid pressure source, and oneventing connection (41, 42).
 10. The system of claim 9 in which eachsaid multiposition valves (35, 36) is an electrically controlledmultiposition valve.
 11. The system of claim 9 including at least onesensor (9, 10) electrically coupled to the control unit and operable fordetecting at least one position of the yarn guide elements.
 12. Thesystem of claim 11 in which said sensor (9, 10) operatively operateswith the piston (23) of the work cylinder (6).
 13. The system of claim 9in which said sensor (9, 10) is a speed sensor.
 14. The system of claim9 including at least two sensors (9, 10) located within the course ofmovement of face ends of a cross winding (14) formed on the tube. 15.The system of claim 9 in which the control unit (8) is operable forcontrolling the work cylinder (6) to prevent ribbon windings and/or ahigh edge buildup at the face ends of the cross-wound winding.
 16. Thesystem of claim 1 including a sensor for detecting the diameter of thecross winding (14) at least one point.
 17. The system of claim 1 inwhich said cable has a round cross section.
 18. The system of claim 1 inwhich said cable is a band (75) with a flat cross section.
 19. Thesystem of claim 1 in which said cable is movable relative to said endface bore without an auxiliary sealing member between the bore andcable.